Ex vivo trypanocidal activity of 1-(2-hydroxybenzylidene)thiosemicarbazide against Trypanosoma equiperdum

Trypanosoma equiperdum is the causative agent of dourine, a venereal disease in horses and donkeys. This parasite has a widely distribution, is found in Africa, Asia, Southern and Eastern Europe, Russia, Mexico and Venezuela. The T. equiperdum is morphologically indistinguishable to other Trypanozoon species, however differs from other mammalian trypanosomes due to the fact that it is primarily a tissue parasite, generating cutaneous plaques, swelling of genitalia and neurological signs. The aim of this study was to evaluate the trypanocidal effectiveness of a set of derivatives of thiosemicarbazones on a T. equiperdum ex vivo culture. All compounds appeared to have trypanocidal activity, however one of them shown better solubility and a dose-dependent effect. The median inhibitory concentration (IC₅₀) was 1.2μM. The selected compound exhibits a greater inhibitory activity than diminazene aceturate, a common drug for animal trypanosomosis treatment.

SARS CoV subunit vaccine: antibody-mediated neutralisation and enhancement

1. A SARS vaccine was produced based on recombinant native full-length Spike-protein trimers (triSpike) and efficient establishment of a vaccination procedure in rodents. 2. Antibody-mediated enhancement of SARS-CoV infection with anti-SARS-CoV Spike immune-serum was observed in vitro. 3. Antibody-mediated infection of SARS-CoV triggers entry into human haematopoietic cells via an FcγR-dependent and ACE2-, pH-, cysteine-protease-independent pathways. 4. The antibody-mediated enhancement phenomenon is not a mandatory component of the humoral immune response elicited by SARS vaccines, as pure neutralising antibody only could be obtained. 5. Occurrence of immune-mediated enhancement of SARS-CoV infection raises safety concerns regarding the use of SARS-CoV vaccine in humans and enables new ways to investigate SARS pathogenesis (tropism and immune response deregulation).

Identification of mu-opioid receptor epitopes recognized by agonistic IgG

We have previously reported the presence of IgG antibodies with a morphine-like activity in the serum of healthy individuals. The agonistic activity of IgG was dependent on their binding to the first and the third extracellular loops of the human mu opioid receptor. In this study we show that IgG antibodies obtained by immunizing rats with peptides corresponding to these two loops exhibited a similar morphine-like activity. Residues corresponding to Y(130), M(132), G(133), T(134) within the first and F(315) within the third extracellular segment were required for antibody binding and conferred to IgG a high mu-opioid selectivity.

[Half-body irradiation. Palliative efficacy and predictive factors of response in 78 procedures]

BACKGROUND

Assessment of palliative effect of hemibody irradiation (HBI) and response-related factors.

METHODS

Analysis of prospective collected data of 78 procedures on 71 patients with multiple symptomatic bone metastases, treated with 6 Gy (upper half-body) or 8 Gy (lower half-body) HBI in single fraction. Clinical improvement was quantified by self-evaluation on a visual analogic scale (SVAS) before HBI, and at 24, 48 and 72 hours, at 7 days, and at each monthly control until patient's death. Univariate analysis included: sex, Karnofsky's index, tumor origin, histology, HBI dose, and SVAS before treatment. For statistical purposes the significance level was 0.05.

RESULTS

Complete (37.5%) or partial responses were observed in 72/78 (92.3%) procedures, 80% appearing during the first 72 hours. Difference between mean SVAS, before and after treatment (7.7 +/- 1.5 vs 2.8 +/- 2.5), was statistically significant (p < 0.001). A mean response duration of 101 days over a mean overall survival of 141 days implies the 70% of expected patient's life span. Any analyzed prognostic factor does not correlate significantly with HBI response.

CONCLUSIONS

HBI is a powerful palliative treatment in patients with multiple symptomatic bone metastasis.

A single dose of granulocyte colony-stimulating factor modifies radiation-induced death in B6D2F1 mice

Granulocyte colony stimulating factor (G-CSF) stimulates the proliferation of progenitor cells committed to myeloid differentiation. In animal models, G-CSF is able to stimulate granulocyte recovery and promote survival after lethal or sublethal irradiation when administered as daily injections, suggesting an influence on the residual hematopoietic primitive precursors surviving irradiation. In this study, we clearly demonstrate that a single dose of G-CSF (1 mg/kg) administered to B6D2F1 mice 2 hours after a lethal dose 95/30 irradiation achieves a 78% survival at day +30 after irradiation. Survival of G-CSF treated mice compares favourably with that of syngenic bone marrow transplantation recipients (78% vs 90%, ns).